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Nanostructured polyamide 12(PA12)/polyketone (PK) blends were fabricated by melt compounding. The nanoscale droplet and domain-in-domain morphologies depending on PK content were observed. When the content of PK was 10 vol%, the impact strength of the blend jumps from 6.8 to 111.9 kJ/m2 and further improved with an increasing content of PK. The tou...
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... At particular frequencies, distinct functional groups present in the sample absorb infrared radiation [49]. Transmittance diminishes when the concentration or presence of absorbing functional groups increases [50]. The composition of the sample can be altered during analysis due to thermal or chemical breakdown. ...
The utilisation of additive manufacturing is essential in the production of intricate and complex parts that cannot be manufactured using traditional manufacturing methods. Despite the complexity of the manufacturing process, parts produced using techniques such as FDM and SLS may include imperfections that diminish the strength of the final products. Post-processing was necessary to increase their strength despite the fact that defects are unavoidable due to the use of advanced manufacturing techniques. Post-heat treatment of FDM- and SLS-printed specimens is assessed using mechanical testing and microscopic analysis. Both the FDM- and SLS-printed parts were discovered to be significantly impacted by post-heating, with the SLS-produced parts being more impacted. After undergoing the heat treatment process, the FDM-printed parts exhibited an average tensile strength of 39.11 MPa, a surface roughness of 2.13 µm, a Shore D hardness of 58.79, and a specific wear rate of 21.21 × 10–5 kg/Nm. After undergoing the heat treatment process, the SLS-printed parts exhibited an average tensile strength of 28.06 MPa, a surface roughness of 2.4 µm, a Shore D hardness of 49.48, and a specific wear rate of 17.49 × 10–5 kg/Nm. The FDM- and SLS-printed components' tensile and hardness properties increased by 21.98 and 6.5%, respectively. The FDM-printed parts' surface roughness and wear rate were lowered to 24.83 and 21.1%, while the SLS-printed parts' were reduced to 51.67 and 50.3%. It proved that SLS-printed components are highly influenced, and that thermal treatment dramatically improved their mechanical properties.
... This might be because it is rather difficult to image microscopic crystalline and amorphous domains, especially for thin filament crosssections. Up to now, polarized optical microscopy [59][60][61][62], transmission electron microscopy [63], and atomic force microscopy [64], have mostly been used to image crystalline domains (e.g. spherulites) in polymer films. ...
A high-resolution Raman mapping method has been developed in order to obtain 2D information about structural anisotropies (crystallinity, molecular alignment) in thin filament cross-sections (diameters between 27 μm and 79 μm). Cross-sections of melt-spun, hot-drawn poly (ethylene terephthalate) (PET) filaments and bicomponent core-sheath PET-polyamide 6 (PA6) filaments have been scanned through a laser beam (spatial resolution < 1 μm). Raman spectra were analyzed with a specifically developed peak fitting method to obtain Raman maps, e.g., mapped peak height ratios across the face of the fibers. These maps reveal microscopic interconnected networks of crystalline strands within a low crystalline matrix. Radial gradients in PET crystallinity, as well as average and surface crystallinities, were determined. The presented Raman mapping method to visualize variations in the PET crystallinity across such fine filament cross-sections, and the findings thereof, open a new pathway to better understand how fiber processing parameters affect radial fiber structures.
... The ketone groups of PK-NaCl nanober membrane can be converted to hydroxyl groups using NaBH 4 and the broad hydroxyl band (-OH) at 3200-3600 cm À1 in Fig. 3d conrms the successful conversion aer the reduction modication. [30][31][32] This reduced PK-NaCl nanober membrane was dened as rPK-NaCl. The contact angle of the PK-LH microber membrane, the PK-HH microber membrane, the PK-NaCl nanober membrane and the rPK-NaCl nanober membrane were given in Table 4 and Fig. 4. The PK-LH microber membrane had a hydrophilic contact angle of $60 and the PK-HH microber membrane demonstrated a hydrophobicity with a measured contact angle of $95 . ...
In this article, polyketone (PK) micro/nano fiber membranes were successfully fabricated by electrospinning and a post treatment process and the membrane characteristics were investigated. The morphology of the fiber membranes showed that ambient humidity during electrospinning changed the roughness of the fiber surface and the addition of NaCl decreased the fiber diameter. In particular, the changes in surface roughness was a very rare and novel discovery. The effect of this discovery on membrane properties was also analyzed. Additionally, the nanofiber membrane was modified by in situ surface reduction. FT-IR spectroscopy indicated the successful reduction modification and water contact angle results proved the improved wetting ability by this modification process. DSC and TGA analysis showed that the micro/nano fiber membranes possessed a high melting point and thermal decomposition temperature. Mechanical tests showed that as fiber membranes, PK micro/nano fiber membranes had relatively high mechanical strength, furthermore the mechanical strength can be easily enhanced by controlling the fiber morphology. From these results, it was concluded that the PK micro/nano fiber membranes could be a promising candidate for many applications such as organic solvent-resistant membranes, high-safety battery separators, oil–water separation, etc.
... The ketone groups of PK-NaCl nanober membrane can be converted to hydroxyl groups using NaBH 4 and the broad hydroxyl band (-OH) at 3200-3600 cm À1 in Fig. 3d conrms the successful conversion aer the reduction modication. [30][31][32] This reduced PK-NaCl nanober membrane was dened as rPK-NaCl. The contact angle of the PK-LH microber membrane, the PK-HH microber membrane, the PK-NaCl nanober membrane and the rPK-NaCl nanober membrane were given in Table 4 and Fig. 4. The PK-LH microber membrane had a hydrophilic contact angle of $60 and the PK-HH microber membrane demonstrated a hydrophobicity with a measured contact angle of $95 . ...
We have developed a very simple approach for preparing physically embedded gold cores in a temperature-responsive hydrogel polymer nanoparticle under fluorescent light irradiation. The complete encapsulation of the multiple gold core nanoparticles is confirmed by the catalytic reduction of 4-nitrophenol, whose reactivity is significantly retarded above the lower critical solution temperature (LSCT) due to the deswelled polymer structure; its increased hydrophobicity slows the access of hydrophilic reactants to the cores. Since these gold cores are physically embedded in the polymer nanoparticles, further growth of the cores is reliably achieved in situ under light irradiation. Interestingly, the resulting composite nanoparticles exhibit reversible solution color changes as well as absorption bands from the visible to near-IR regions below and above the LSCT.
To enhance the low‐temperature toughness and resistance of the engineering plastic polyamide PA12, this study introduces novel PA12/MVQ@POE‐g‐MAH ternary composites using a two‐step process and dynamic curing. Analytical results indicate that incorporating MVQ@POE‐g‐MAH into the PA12 matrix markedly enhances its toughness and heat resistance. As the MVQ@POE‐g‐MAH content increases, the elongation at break of PA12 composites significantly expands from 52.83% to 204.69%, and the notch impact strength escalates from 8.69 to 74.34 kJ/m ² . Additionally, the brittleness temperature of PA12 decreases from ‐59.5 to ‐67.0 °C. Experimental findings confirm that POE‐g‐MAH is dispersed at the interface between MVQ and PA12, creating an encapsulated structure of MVQ@POE‐g‐MAH. This enhancement significantly broadens the potential applications of PA12 by improving its toughness, and resistance to both low and high temperatures, as well as impact endurance.
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In this study, the impact of two compatibilizers, ethylene terpolymer (C1) and maleic anhydride grafted polyethylene (C2), on the mechanical, thermal, and tribological properties of 30% glass-fiber-reinforced polyketone (PK) and polyketone/polyamide 6 (PK/PA-6) blend composites was investigated. In the case of 30% glass-fiber-reinforced PK composites, the mechanical test results showed that C2 significantly improves the impact resistance (over 48.8%) and elongation at break (over 13.3%) values due to the enhanced compatibility between glass fibers and the PK matrix, attributed to the maleic anhydride functionality. The tensile and flexural properties of the 30% glass-fiber-reinforced PK/PA-6 blend composites were determined to be between the values of pure PK/GF30 and PA-6/GF30 composites, which were its constituent components. Notably, these blend composites displayed higher impact resistance (19.6 kJ/m2) and elongation at break (4.86%) values than the pure PK/GF30 and PA-6/GF30 composites. The SEM images suggested that C2 creates a better interface between glass fibers and the matrix, resulting in a more cohesive structure. Differential scanning calorimeter analysis revealed two distinct glass transition temperatures, indicating the existence of two phases, and reflecting the immiscibility of the two polymers. Tribological studies showed that the friction coefficients and specific wear rates of PK/PA-6/GF30 composites were improved by increasing PK segment. The PK-25/PA6-50/GF30-C2 sample exhibited a friction coefficient of 0.341 μ and a specific wear rate of 1.15 10¯6 mm3/Nm. Overall, the C2 proved to be a more suitable compatibilizer than C1, offering valuable insights for tailoring high-performance materials with enhanced properties.
The influence of two compatibilizers, ethylene terpolymer (C1) and maleic anhydride grafted polyethylene (C2), on the mechanical, thermal, and tribological properties of 30% glass-fiber-reinforced polyketone and polyketone/polyamide 6 blend composites was investigated. Based on, mechanical, microscopic, thermal, and tribological results, the C2 was found to be a more suitable compatibilizer than C1 for improving the interface between glass fibers and the matrix
Compatibility and physical properties of aliphatic polyketon (PK)/polyamide 6 (PA6) blend were investigated. The PK and PA6 showed high adhesion strength and thus impact strength of PK/PA6 blends was very high. It was observed that PK-PA6 copolymers are formed by a chemical reaction between the two polymers and the copolymers act as a reactive compatibilizer in the PK/PA6 blends. The presence of the PK-PA6 copolymer was confirmed by FTIR analysis. The adhesion strength between PK and PA6 was very high compared to a typical incompatible polymer pair. PA6 investigated herein has two end groups, NH 2 and carboxylic acid. We also adopted end-capped PA6 that has two carboxylic acid end groups. The adhesion strength and impact strength of the PK/end-capped PA6 blends was much lower than that of PK/PA6 blends. More importantly, the PK-PA6 copolymer was not formed in the PK/end-capped PA6 blends. Thus, it was concluded that the chemical reaction occurs between the carbonyl of PK and the primary amine end group of PA6. Due to the high impact strength of PK/PA6 blends, possible applications could be automotive parts where higher impact strength is required.
The compatibility of polyketone (PK)/polyamide 6 (PA) polymer blends was studied to expand the use of PK polymers with polyamide 6 blends. Tensile strength showed negative deviation, but flexural modulus and Izod impact strength showed positive deviation with composition according to the linear mixing law. Differential scanning calorimetry and X-ray diffraction analyses showed that little shift in the glass transition temperature (Tg) and diffraction angles of the blends. Tg shifts were observed in the PK-rich and PA-rich compositions in dynamic mechanical tests, but a broadened bandwidth of tanδ peak and shoulder peaks were present in the PK30/PA70 and PK50/PA50 ranges. The blend morphology showed good interfacial adhesion and appeared as submicron domains in the PK-rich and PA-rich blends. Interfacial adhesion and the domain sizes larger than the critical size of the blend contributed to the improved impact strength of the PK/PA blend. Infrared spectroscopy showed that the hydrogen bonds in each polymer chain were reduced in blending, indicating a certain level of molecular blending between the PK and PA polymers. The results of this study suggest that PK/PA blends are partially miscible.
